The present invention relates to a device for inspecting a tube by ultrasonics.
The device according to the invention comprises a probe constituted by an ultrasonic transducer fixed to a mirror which receives the ultrasonic wave emitted by the transducer and centred on the axis of the probe, means for moving the probe within the tube to be inspected and means for detecting ultrasonic echos reflected by the tube.
The device according to the invention also comprises means for introducing an acoustic coupling liquid into the volume between the tube, transducer and mirror when the probe penetrates the tube to be inspected and for discharging said liquid when the probe leaves the tube, said means substantially comprising a flexible pocket reservoir filled with liquid and placed in the lower part of the probe and connected to the volume to be supplied with liquid, whereby said pocket is flattened when it penetrates the tube to be inspected following the probe, which has the effect of expelling part of the liquid contained therein in the direction of said volume, the said liquid returning by gravity into the pocket when the latter leaves the tube under inspection and reassumes its shape.
The device according to the invention can be adapted to the detection of transverse or longitudinal faults in tubes, as well as to the measurement of diameter and thickness of tubes. In the latter case it comprises a rotary perforated screen, positioned between the transducer and the tube to be inspected. The mirror which receives the ultrasonic wave emitted by the transducer can be:
Conical, with an apex angle of 90.degree. .+-. i, for detecting transverse faults with an incidence i ; PA1 Conical, with an apex angle equal to 90.degree. , for measuring the radial dimensions; PA1 Helical for detecting longitudinal faults.